Filming takes place as the world’s first synthetic burger is cooked during a launch event. Photograph: Toby Melville/Reuters

The most expensive hamburger in the world began, about three months ago, with cows raised on organic farms.

There was, however, very little traditionally pastoral about the way it was made: the process started with the extraction of stem cells from a biopsy of two cows, a blanc blue belge and a blond acquitaine.

Dr Mark Post and his team at Maastricht University used these cells to grow 20,000 muscle fibres in individual culture wells, each one a tiny hoop of greyish-white protein suspended in a gel-like growth medium that contained antibiotics and a serum extracted from cow foetuses.

After a few weeks of growth, each hoop of fibre was removed by hand, cut open and straightened out. The fibres were then pressed together, coloured with beetroot juice and mixed with saffron, breadcrumbs and some binding ingredients to form the burger – biologically identical to beef, but grown in a lab. The total cost of the project was €250,000 (£215,000), funded by Google co-founder Sergey Brin.

"It's really just proof of concept right now, we're trying to create the first cultured beef hamburger," said Brin in a film to mark the tasting event in London on Monday. "From there I'm optimistic that we can really scale by leaps and bounds."

Brin said he had been moved to invest in the technology for animal welfare reasons. People had an erroneous image of modern meat production, he said, in terms of "pristine farms" with just a few animals in them. "When you see how these cows are treated, it's certainly something I'm not comfortable with."

Monday's event in London, in which a chef cooked and served the synthetic burger in public, was the culmination of years of research by Post aimed at demonstrating that this method of growing protein could one day be a viable alternative for meat from livestock.

"Cows are very inefficient – they require 100g of vegetable protein to produce only 15g of edible animal protein," Post told the Guardian before the event in London. "So we need to feed the cows a lot so that we can feed ourselves. We lose a lot of food that way." With cultured meat, scientists can make meat production more efficient because they can keep all the variables under control. They also do not need to slaughter any cows.

The human appetite for meat means that 30% of the Earth's usable surface is covered by pasture land for animals, compared with just 4% used directly to feed humans. The total biomass of our livestock is almost double that of the people on the planet and accounts for 5% of carbon dioxide emissions and 40% of methane emissions – a much more potent greenhouse gas.

By 2060, the human population is predicted to rise to 9.5 billion and, with a rising demand for meat from rapidly developing populations in, for example, China and India, the market in meat is expected to double by the middle of the century. If the amount of meat we produce doubles, livestock could be responsible for half as much climate impact as all the world's cars, lorries and aircraft. In 2008, Dr Rajendra Pachauri, chair of the UN intergovernmental panel on climate change, urged people to have one meat-free day a week to help curb climate change.

Different methods of growing meat in labs will have different impacts on the environment, and Post said early indications were that his lab meat reduced the need for land and water by 90% and cut overall energy use by 70%.

The best way to prevent this environmental damage, of course, would be if everyone could be persuaded to eat less meat. But no one thinks that will happen – the desire to eat meat is ingrained deep in our evolution, according to Harvard University primatologist Prof Richard Wrangham.

He argues that learning how to cook and eat meat was one of the reasons that human brains were able to grow as big as they did. Meat, a dense source of nutrition and calories, powered our ancestors' brains in a way that their competitors could not match and has had a lasting impact on our species' taste for flesh today.

"The fact is that people have a very strong tendency to enjoy meat, which is doubtless because of all the advantages it gave during human evolution, including access to rare micronutrients – for example salt, iron, zinc – and a good source of fat, as well as a chunk of calories," said Wrangham.

"We can't precisely rank the various benefits meat gave, but we can definitely say that hunter-gatherers everywhere were hugely desirous of getting it."

Cultured meat, said Prof Wrangham, should be embraced for this reason alone — because humans like meat so much. "It is a practical matter: people are going to continue wanting meat, and a system of meat production that reduces the environmental and ethical costs will be a great benefit."That ancient taste for meat would provide a willing market for cultured products, says the food writer and commentator Jay Rayner, when the technology can be perfected. "What you'll [eventually] see is a separation. On the one side you'll have your prime cuts, these will be special-occasion meats – if you want a steak or a joint or a whole chicken, you'll get those things, but less regularly than you do now. But if you want animal protein to make, perhaps, a cheap burger or a lasagne or something like that, then you'll go for alternatives, which may be in vitro meat or it may be insect protein."

Traditionally farmed meat is already very expensive, Rayner adds, and will only get more so, and it is only a matter of time before members of the public begin to embrace alternatives.

There are many hurdles before Post can scale up his process for large-scale manufacture – cell culture is not cheap – but he has high hopes. "Twenty years from now, if you have a choice in the supermarket between two products that are identical and they taste and feel the same and have the same price – and one is made in an environmentally friendly way, with far fewer resources and provides food security for the population and doesn't have any animal welfare connotations to it – the choice will be relatively easy," he said. "People will start to prefer this type of product and then it will gradually transform meat production."

The first hamburger he has made is relatively simple, just pure protein. It may be good enough as a proof of concept, but it is far from being a seamless replacement for meat. For a start, it has no fat or blood, which is where much of the flavour of meat comes from.

Next on the agenda, therefore, for Post's team is to add lab-grown fat cells to the protein, and perhaps even bone cells for those who want a fully lab-cultured T-bone steak. "The technology now is confined to small pieces because you have to get oxygen and nutrients into the tissue to keep it alive," he said. "For larger pieces we need to develop different technologies that have been described in the medical field, but have not been applied to meat production yet." That means building something a bit like blood vessels into the meat, which could provide fluid, oxygen and nutrients to the centre of the tissue as it grows.

Post acknowledges that it will be essential to produce a product that looks and tastes exactly the same as real meat. And if they find there is a market for cultured beef, the same methods could be used to grow other proteins such as chicken, lamb, fish or pork in the lab.

Critics may argue that holding a public event to showcase the work instead of presenting results in a peer-reviewed journal could alienate scientific colleagues, who will be sceptical about the work. Post's response is that most of the methods he is using – involving engineering and growing large numbers of cow stem cells – have already been published in journals. His hamburger, he said, was more a result of brute force in growing more material than anyone else has so far. "From the technological point of view there are very few secrets here," he said.

Any cultured meat for sale to the public would also need to be proved safe. The Food Standards Agency said that "any novel food, or food produced using a novel production process, must undergo a stringent and independent safety assessment before it is placed on the market". The FSA said there had been no such applications to date.

On the welfare front, Julian Savulescu, professor of practical ethics at the University of Oxford, said that laboratory-grown meat scores high. "Artificial meat stops cruelty to animals, is better for the environment, could be safer and more efficient, and even healthier. We have a moral obligation to support this kind of research. It gets the ethical two thumbs up."

Brin said he was interested in investing in technologies that were "on the cusp of viability. If it succeeds there, it can be really transformative for the world."

He acknowledged that some people would probably think synthetic meat was science fiction. "I actually think that's a good thing. If what you're doing is not seen by some people as science fiction, it's probably not transformative enough."